THE UNIVERSITY OF UTAH is a much stronger Children's Cancer Study Group (CCSG) institution since Dr. O'Brien became principal investigator. Total registrations on CCSG studies have increased substantially. We have averaged 89 total on-study and 53 therapeutic study registrations per year over the last 3 years. This represents an 88% increase in total on-study and a 47% increase in therapeutic study registrations compared to the 3 previous years. We also have an excellent record for participation in the entire breadth of CCSG studies. Utah's major scientific leadership contributions in CCSG have been in the areas of LATE EFFECTS, BRAIN TUMORS AND PATHOLOGY. Dr. O'Brien has assumed a major leadership role in the area of late effect and is Vice Chairman of the Surveillance and End Results Committee. He has been instrumental in getting late effects questions incorporated prospectively in many first-line studies. He played a critical role in the development of the first prospective study of neuropsychologic effects of ALL (CCG-105NP) and in the initiation of the Psychology Committee. He is Vice Chairman of the advanced Hodgkin's disease study which has late effects questions as major objectives. In addition, Dr. O'Brien is a member of the Brain Tumor Strategy Group and Coordinator for all active CCSG brain tumor studies. Utah has a very strong CCSG pathology record. Drs. Wilson & Kjeldsbergs' work has had a profound effect on the development of all CCSG lymphoma studies. They described for the first time the critical influence of specific histologic subtype on prognosis and response to therapy in non-Hodgkin's lymphoma and developed a successful curriculum for institutional pathologists aimed at distinguishing lymphoblastic from non-lymphoblastic lymphomas. Their work as review pathologists for most lymphoma studies has led to Utah becoming essentially a CCSGlymphoma reference laboratory. Dr. Kjeldsberg is a member of the Hodgkin's and non- Hodgkin's Lymphoma Strategy Groups. Dr. Pysher is a member the Soft Tissue Sarcoma Strategy Group and the member of the Pathology Steering Committee responsible for the annual Pathology Workshops. Utah is in a growth phase within CCSG in terms of both patient registrations & scientific leadership. We have investigators on 4 of the 8 CCSG Strategy Groups and the Steering Committee of 2 Discipline Committees. This is where the scientific future of the Group is being determined.